Controlling system for electric motors.



No. 764,439. PATENTED JULY 5, 1904,

' A. c. EASTWOOD.

CONTROLLING SYSTEMFOR ELECTRIC MOTORS.

APPLICATION FILED MAR. 21- 1904.

N0 MODEL. 5 SHEETS-SHEET 1.

m \um I J' I I No. 764,439. PATENTED JULY 5, 1904.

A. C. EASTWOOD. CONTROLLING SYSTEM FOR. ELECTRIC MOTORS.

APPLICATION FILED MAR 21. 1904.

PATENTED JULY 5, 1904. A. G. EASTWOOD. CONTROLLING SYSTEM FOR ELEGTRICMOTORS.

APPLIOATION FILED MAR. 21. 1904.

5 SHEETS-SHEET .3.

HO MODEL.

No. 764,439. PATENTED JULY 5, 1904. A. C. EASTWOOD. CONTROLLING SYSTEMFOR ELECTRIC MOTORS.

APPLICATION FILED MAR. 21. 1904.

5 SHEETS*SHEET 4.

NO MODEL.

mhwdw m ML zhw% r u fifim 7% M N0. 764.4:39 PATENTED'JULY 5,, 1904.

A. O. EASTWOOD. CONTROLLING SYSTEM FOR ELECTRIC MOTORS.

AFPLIOATION FILED MAR. 21, 1904 Patented July 5, 1904.

PATENT OEEIOE.

ARTHUR o. EASTWOOD,

OF CLEVELAND, OHIO.

CONTROLLING SYSTEM FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 764,439, dated July 5,1904.

Applieationfilcd March 21, 1904.

To all whom, it may concern.-

Be it known that I, ARTHUR O. EASTWOOD, a citizen of the United States,and a resident of Cleveland, Ohio, have invented certain Imthrough amotor at the instant of its reversal to a value which the motor willsafely stand,

' and also contemplates the use of means for automatically cutting outthe starting resistance of the motor in such manner that the currentflowing will not exceed a predetermined sate value.

The invention further includes reversing mechanism and adjustable meansfor regulating thespeed of a motor such that when said means has beenset for a certain speed the motor will be automatically reversed andaccelerated to the predetermined speed, again reversed at apredetermined time and accelerated to a given speed in the reversedirection, and so on. The arrangement of parts is such that the speedsattained by the motor when operating in opposite directions may be andgenerally are different, since when the motor drives a reciprocatingmachine, such as a planer, a cut is generally made while thereciprocating part is moving in but one direction, and it is desirableto return said part on its idle stroke as rapidly as possible.

With the object of advantageously Operating a motor in the mannerindicated 1 have provided the system hereinafter described, referencebeing had to the accompanying drawings, in which Figure l is adiagrammatic view showing my invention as applied to the automaticcontrol of a compound-wound motor, the speed variation being obtained byadjusting a variable resistance in circuit with the shunt field-'winding. Fig. 2 is a diagrammatic View illustrating the connectionsbetween the automatic switches, the starting resistance, and thearmature oi' the motor illustrated in Fig. 1, the whole being shown forthe sake of clearness as independent of the other connections.

Serial No. 199,123. (No model.)

Fig. 3 is a diagrammatic view illustrating my invention as employed forthe automatic control of a compound-wound motor, the speech -with bothadjustable and non-adjustable resistance in the shunt field-winding ofsaid motor. Fig. l is a diagrammatic view showing my invention asapplied to the automatic control of a shunt-wound motor, the speedvariation being obtained by supplying the armature of the motor with thevarious voltages of a four-wire circuit and in employing an adjustableresistance in the shunt field-wind ing. Fig. 5 is a diagrammatic viewillustrating the distribution of voltages between the wires of thecircuits supplying the apparatus illustrated in Fig. 4. Fig. 6 is a sideelevation, to some extent diagrammatic, showing a planer equipped with acontroller for reversing the motor from which said planer is driven; andFig. 7 is a diagrammatic view of a special form of the systemillustrated in Fig. 1.

Hitherto reciprocating machines such as metal planers, for example havebeen driven either by a pair of belts running in opposite directions andshifting alternately from tight to loose pulleys or through some form ofclutch.

lVith the belt-drive there is ordinarily but a single cutting speedpossible, which speed in general is too low for cutting cast-iron withmaximum efficiency and too high for cutting steel without rapiddepreciation of the cuttingtool.

With the clutch-drive a plurality of speeds has in some cases beensecured by changing the gear ratio between the clutch which imparts thecutting motion to the platen of the ,planer and the driving-shaft of theplaner.

Such an arrangement is relatively costly, as well as complicated, andthe range of speed secured is not sufiicient to permit of the tool beingworked at its maximum cutting eiiiciency on all materials operated uponin the ordinary run of machine-shop work. For

I this reason the metal-planer has in the past been oneof the mostinefficient of tools, and

the same may be said of many other formsof reciprocating machines, suchas various forms of printing-presses and the like. g

By my invention I provide a system by means of which a driving-motordirectly connected or geared to the platen of a planer or tothe'oscillating or reciprocating part of any machine can be reversed ateach end of each gears.

The problem of reversing a motor connected to a load may be resolvedinto two partsfirst, the absorption and dissipation of the energy of therotating armature and of the load to which it may be connected, due totheir forward motion, and, second, the acceleration of the combinedmasses of the armature and the load in a reverse direction.

With the controlling devices at present known to the art the reversal ofthe current through one of the members of the motor while the armatureis in motion causes a very heavy rush of current to take place throughsaid armature, and this is not only injurious both to the windings andtothe commutator, but in addition produces mechanical strains which may beinjurious to the gearing and to the machine operated by the motor.

The abnormal current flowing after the direction of current-flow hasbeen reversed and before the direction of rotation of the armature hasbeen reversed is due to the fact that during the time interveningbetween these occurrences the counter electromotive force generated bythe armature, due to its forward revolution, acts in the same directionas the newly-applied electromotive force, so that the total voltageactive to force current through the windings of the motor may be nearlydouble the applied electromotive force.

In general I prefer to use a compoundwound motor in carrying out myinvention, although, as hereinafter described, it is possible toadvantageously employ a shunt-wound motor. A compound-wound motor willproduce a greater torque at the instant of reversal onaccount of theeffect of the relatively heavy series-field current and will thereforetend to accelerate a load more rapidly than would otherwise be the case.Since, however, such a motor has a tendency to reduce its speed under anincrease in load and as variation in speed due to variation of load whenmaking a working stroke is undesirable, I use the series field-windingonly during the period of reversal and acceleration, thereaftershort-circuiting said winding and continuing to operate the motor as asimple shunt-wound machine for the remainder of theworking stroke.

For varying the speed of the motor where a very wide range is notrequired I may use a single applied voltage and adjust the speed byinserting more or less resistance in the shunt field-winding of themotor, while where a wider range of speed is required I may secure thedesired variation by applying various voltages to the armature of themotor either with or without an adjustable resistance, inserted incircuit with the shunt field-winding.

In the drawings and description following I have illustrated anddescribed three cases to which my improved system of control may beadapted, although it will be understood that I do not limit myselfsolely to these particular applications, since it is possible toconceive of other combinations of apparatus by which the same end asthat obtained by my invention would be secured, but which wouldsiminvention.

In Figs. 1 and 2 I have illustrated my im proved system as adapted tothe automatic control of a compound-wound motor whose speed of operationis adjusted by varying its field strength. Current is supplied from apair of mains through a main switch Q, and the apparatus employedincludes a controller C, having a drum actuated by the reciprocatingpart of the machine driven by the motor, whose armature is indicated atA. Said motor has a series field-winding F and a shunt field-winding f,there being a bank of resistance 1 connected to one end of the latter.The amount of this resistance in circuit with the winding f depends onthe position of an adjustable contact-arm r, which engagescontact-buttons connected at intervals to the resistance r. I alsoemploy seven electromagnetic switches S, S, to S, together with twobanks of resistance R and R, connected as hereinafter set forth.

The drum of the controller C is illustrated in Fig. 6 as employed inconnection with a metal-planer, illustrated diagrammatically at Y andprovided with areciprocable platen y, having adjustable dogs and M. Thespindle of the controller-drum has on it a ratchet or toothed wheel 0for engagement with said dogs, so that the drum will be turned to apredetermined extent when either of said dogs is brought into engagementwith said wheel. The controller has upon it two sets of contactsegmentsC and-C of which there are six in one set and five in the other, therebeing also six contact-fingers c 0 to c for engagement with saidsegments. The segments C and are electrically connected, as indicated,and it will be noted that the three segments placed to engage thefingers c and 0 are relatively short, being engaged by said fingersafter and disengaged therefrom before the ply be developments of thebroad idea of said other contact-segments for a purpose set forthhereinafter.

The switches S, S, S to S have solenoidcoils s, 5-, to s, respectively,by which they are actuated, and the first five of them are normally heldopen by any desired means, while tending to close when their respectivecoils are excited. The switch S is normally retained in a closedposition, being opened only when its coil 8 is excited.

The lower terminal of the switch S is directly connected to one terminalof the armature A, while its upper terminal connects, through the bankof resistance R, with the other armature terminal. One end of the coil 8of this switch connects to the lower terminal of the switch, while itsother end is connected to a contact-finger 0 on the controller O.Asecond contact-finger, o is connected to the second terminal of thearmature, and it will be noted that there are on the controller-barreltwo electrically-connected contact-se ments 0', laced so as to en a esaid a b b fingers when the controller is in its off position. Oneterminal of the switch S is clirectly connected to the positivesupply-main through switch Q, while the other terminal of said switchinthe present case the upper oneis connected to one end of a bank ofresistance R, as well as to the lower terminals of the switchesS and Srespectively.

The coil 8 of the switch S has one end connected directly to thepositive supply-main and its other end connected to the finger 0 of thecontroller, and it may be added that under operating conditions theengagement of the said finger with its corresponding contact-segmentsestablishes connection from said coil to the negative supply-main. Oneend of each of the coils s and s is similarly connected to the finger 0and hence, as above noted, to one of the armature-terminals or to thenegative supply-main, while the other end of each of these coils isconnected to that end of the bank of resistance R opposite to the endconnected to the switch S, and hence to the other armature-terminal. Itwill therefore be seen that with these connections the voltage appliedto the coils s and s will be the linevoltage minus whatever drop theremay be through the resistance R.

The switch S has its terminals connected, respectively, with theterminals of the series field-winding F of the motor, so that when saidswitch is closed said winding will be shortcircuited. One end of thecoil 8*, as well as the coil 8 of the switch S is connected to thenegative supply-main in a manner similar to the connection for the coils8, s and 8 while its other end is connected to one of two auxiliaryterminals on the switch S the second of said auxiliary terminals beingin direct connection with the positive supply-main.

The switch S is connected to short-circuit any portion of the fieldresistance 9 which to the negative supply-main.

may be included between the button engaged by the contact-arm 9" and thejunction of said resistance with the shunt field winding f. One end ofthe coil of this switch, as well as one end of the coil s, is connectedto one of two auxiliary terminals on switch S*, the second auxiliaryterminal being connected to the positive supply-main, it being notedthat the two pairs of auxiliary terminals on the switches S and S* areplaced so as to be respectively connected by the blades of said switcheswhen the latter close. The second end of the coil 8 is connected to thefinger c of the controller O, and when the drum of said controller isturned to engage the set of segments indicated by C said coil isconnected \Vhen, however, the drum is turned in the opposite direction,said coil is open circuited, since there is no segment to engage saidfinger.

The switch S has one of its terminals connected directly to the negativesupply-main and the other to the point of junction of the shuntfield-winding f and the resistance r, the opposite end of saidresistance being also connected to the negative supply-main, so that theswitch S when closed short-circuits said resistance. 4

Under operating conditions the main switch Q, is closed and the drum ofthe controller turned so as to bring one set of contact-segments-forexample, the set O-into engagement with the fingers 0* to 0. Thiscorresponds to such a direction of rotation of the motor as will causethe movable motion of the machine to make a working stroke.

i/Vith connections as above indicated, coil 8 of the switch S will beexcited, and said switch will at once he closed, thus closing thecircuit through the motor and starting the same, it being noted thatcurrent flows through all of the resistance R and the series field F ofthe motor. The shunt-field f, having one of its terminals connected tothe positive supplymain and its other terminal connected, through thenormally closed switch S, to the negative supply-main, will also beexcited.

The resistance R is connected to the upper terminals of the switches S,S, and S" and is divided into two sections, each having a resistance offive ohms. The total bank of resistance R has therefore a resistance often ohms, and in the particular case referred to the switch S has itscoil so adjusted that the latter will operate to close said switch whencurrent at a pressure of 73.4: volts is applied to it. Similarly thecoil of the switch S is adjusted to close said switch when current at146.8 volts is applied to it. Assuming that current supplied is at apressure of two hundred and twenty volts, as soon as the switch S isclosed the current flowing will be two hundred and twenty divided byten, or twentytwo amperes, and practically the full-line voltage will atfirst be absorbed by the resistance R, so thatthere will be nodifference of potential between the ends of the coils s and 8 As soon,however, as the armature of the motor begins to revolve the currentflowing will be reduced owing to the counter electromotive force setupby the armature, and this reduction continues until when current flowingis 14.66 amperes the drop through the resistance R is 146. 6 volts.Hence the voltage applied to the coils s and s will be two hundred andtwenty minus 146.6, or 73.4 volts, under which condition the switch Swill immediately close and short-circuit one of the sections of saidresistance R. This will momentarily increase the volume of currentflowing, and consequently speed up the motor. When, owing to theincreased counter electrornotive force the current has again fallen to14.66 amperes, the drop through the second section of resistance R willbe 73.2 volts, so that the voltage applied to the coil s will be 146.8volts. The switch S will therefore close, and thus shortcircuit thesecond section of the resistance R.

In the above assumption 14.66 amperes is taken as the normal runningcurrent of the motor, while the initial current of twenty-two amperesrepresents a fifty-per-cent. overload on the same motor. It willconsequently be noted that the said initial current is limited to a safevalue.

The closing of the switch S by which current is permitted to flowdirectly to the motor from the su pply-mains, also completes the circuitbetween the auxiliary'terminals carried upon it, so that the coil 5 isenergized and the switch S is closed, with the result that the seriesfield-winding of the motor is shortcircuited. Since such action weakensthe field of the motor, its speed will be increased, and inasmuch as theclosing of the switch S has electrically"c0nnected the auxiliarycontacts carried by it both of the coils s and s" will now be excited,thus closing the switch S and opening the switch S. The first of theseswitches acts to short-circuit whatever resistance is included betweenthe junction of the shunt field-winding f and the contact-button engagedby the adjustable arm 1*, while the opening of the switch S will removethe short-circuit from the resistance r, so that the field of the motoris still further weakened by an amount depending upon the quantity ofresistance included between the button engaged by the arm 'I and the endof said resistance which is directly connected to the negativesupply-main.

From theabove it will be seen that there are as many speeds available asthere are contact-buttons to the bank of resistance r, and since thevarious operations described take place in a relatively short time itwill be seen that the motor is automatically brought up to any of thesaid speeds, which, as before noted, depend upon the amount ofresistance in circuit with the shunt field-winding. When the end of theworking stroke of the machine operated is reached, the barrel of thecontroller will be automatically turned by the engagement of the dog 1with the toothed wheel 0 and the contact-fingers 0 to 0" breakconnection with the set of contacts G. Since the contacts engaged by thefingers 0 and 0 are shorter than the main contacts, it will be notedthat any arcing which may occur will take place on the switches S,S ,Sto S instead of on the contacts of the controller, inasmuch as saidswitches will open and cutoff the current before the main contacts aredisengaged by the fingers 0 to 0, inclusive.

While in moving from engagement with the segments 0 to engagement withthe segments 0 the fingersv 0 and o have engaged for a short time withthe electrically-connected segments 0, such engagement is not continuedfor a suificiently long interval to cause the coil 8 to operate theswitch S.

' When the segments C are brought into engagement with the fingers ofthe controller,

the switch S will again automatically close and the circuit will againbe closed, with the direction of current through the armature reversed,The energy contained in the armature and its connected mechanism due totheir forward motion will be dissipated through the resistance R, andthe armature after being brought to rest will begin rotation in adirection the reverse of that hitherto noted.

As before, the switches S and S will close at predetermined tiniesafterthe closing of the switch S, cutting out the resistance R, after whichthe switch S will close, again short-circuiting the seriesfield-winding. The switch S will not close, since its coil has beenopen-circuited owing to there being no segment in the set C which willengage the finger 0 The switch S will finally open, again removing theshort circuit from the field resistance 1'. Under such conditions theentire body of this resistance r is effectual in cutting down thefield-current, and the armature of the motor will be accelerated to itsmaximum speed. At the end of the idle stroke of the machine the drum ofthe controller will be turned to its original position and the firstcycle of operations will be again repeated.

If the controller at any time be thrown to its off position with thefingers c and 0 out of engagement with their contact-segments, thefingers 0 and 0 will engage with the segments 0, and since the armatureof the motor will still be rotating the coil 8 of the switch S will beexcited by the counter electromotive force of said armature. This willclose the switch 'S, so as to establish a circuit including the armatureA and the bank of resistance R, which latter is preferably soproportioned that the maximum counter electromotive force of the motorwill produce in it a current equal to the full-load current. Thegeneration of' this current produces a powerful braking action on thearmature, and consequently on the machine to which it is connected.thereby quickly bringing them to rest. When this condition is attained,there is no furthercounter electromotive force generated, so that thecoil .9 is deenergized and the switch S is permitted to open. As abovenoted, this braking action takes place only when the controller remainsin its ofl? position for an appreciable time, since under ordinaryconditions of automatic operation the segments 0 pass under the fingers0 and 0 so rapidly that the coil 8 has not time to act.

It will be understood from the above description that by my system amotor may be operated at any of a large number of speeds in onedirection, automatically reversed, and then accelerated to a maximumspeed in a reverse direction. I

While the above-described system of operation is particularly applicableto a majority of machines, such as metal-planers, in which a slow-speedworking stroke and a quick return stroke is desired, I do not limitmyself in this particular, as it will be readily appreciated by thoseskilled in the art that similar means may be employed to adjust thespeed of the motor for both strokes of the machine operated. Such amodification of my system is illustrated in Fig. 7, in which acontactsegment has been added to the set C and a contact-finger employedin addition to those already provided. With such an arrangement of partsa second bank of resistance 1' could be employed having contact-buttonsand an adjustable arm 7*. There would also be a normally open switch Shaving an operatingcoil 8 of which one end will be connected to thecontact-finger 0 of the controller C, while the other end of said coilwould, like the coils S and s, be connected to one of the auxiliaryterminals of the switch S. Under operating conditions the amount ofresistance r in circuit with the field-winding f could be adjustedindependently of the resistance r, so as to obtain anydesired speed ofoperation of the motor on its return stroke.

In Fig. 3 is shown my invention as applied to a compound-wound motorsupplied with current from an Edison three-wire system, the speedvariation being obtained by applying one of the two available voltagesto the armature, with or without resistance, and also by adjusting theamount of resistance in circuit with the shunt field-winding of themotor. In this diagram Q illustrates the main switch interposed betweenthe positive, neutral, and negative supply-mains and the controllingsystem. In place of the adjustable contact-arm and contact-buttonsconnected at intervals to the resistance r I provide in the present casea series of contact-fingers connected directly to said resistance andprovide also a series of segmental contact-pieces (Z (Z d (P, and (Zmounted upon a drum in the well-known manner. In addition to saidfingers there are other fingers (1 and (Z mounted so as to coact withsegments (Z and (Z and it will be seen that all of the segments on saiddrum are in electrical connection, with the exception of the twoindicated by the reference-letter (Z which are, however, independentlyconnected to each other. As in the system illustrated in Fig. 1, thereis a controller (J, actuated by the machine operated as beforeexplained, while the controller D, hav. ing the resistance r, can beoperated by hand, so as to bring any of its various segments intoengagement with the contact-fingers (Z, (Z and (Z The controller has, inaddition to the fingers and contact-segments described in the first formof my invention, other fingers c and 0 provided with twoelectrically-connected segments on the controller-barrel for a purposehereinafter set forth. There is also a finger 0 and a correspondingsegment on the barrel, placed so as to be one of the set of contacts (Jand in electrical connection with the segments engaged by the fingers cand 0 As before, there is a magneticallyoperated switch S connectedacross the armature-terminals and having in circuit with it a body ofresistance R, the coil 8 of said switch being connected, as previouslydescribed, so as to be energized by the armature-current when thecontroller C remains in its off position for an appreciable time. Thenegative supply-main is connected to one end of the series field-windingF, while the neutral main is connected to the lower terminal of a switchS, and the positive main is connected to the upper terminal of a switchS. In addition to the above there are other switches S S S S and S, ofwhich the switch S is double-acting, there being contacts on both theupper and the lower ends of its switch-bar and corresponding terminalsfor the same. This switch is normally held with the lower endof its barin engagement with the lowermost of these terminals. The banks ofresistance R and R are connected, respectively, between the upperterminals of switches S" and S and S and S and the upper contact ofswitch S is also connected to the lowermost contact of the switch S,while the'uppermost contact of the switch S is connected to the positivesupply-main. The upper terminal of the switch S is connected to thelower terminal of the switch S while the lower terminals of the switchesS and S are connected together and to the finger c of the controller C.The terminals of the switch S are connected, similarly to those of theswitch Si referred to in the first case described, to the terminals ofthe series fieldwinding F, while the terminals of the switch S areconnected to the bank of resistance r, so that this switch while in itsnormally closed position short-circuits said resistance.

- cuit the resistance R and thus still further- Switch S,which is alsonormally closed, is connected to sh'ortcircuit a second bank of fieldresistance 7". There are upon switch S a pair of auxiliary terminalselectrically connected when said switch is closed, one of thesecontacts, being connected to the finger c of the controller C, while theother is connected to an auxiliary terminal of the switch S and to oneend of the solenoid-coil of the switch S Thesecond auxiliary terminal ontheswitch S is in turn connected to an auxiliary terminal on the switchS and to one of the fingers (Z on the controller D. The. secondauxiliaryterminal on the switch S is connected to one end of each of theso- S will at once cause said switch to close, thus supplying thearmature of the motor with current at one hundred and ten volts, whichWlll flow from the neutral supply-main through the resistance R to thelowermost terminal of switch S and thence to its center contact throughthe controller C, the armature of the motor, the series field-winding F,and the negative supply-main. hem-as in the first case described, thecurrent has been sufficiently reduced by the counter electromotive forceof the armature, the switch S will automatically close so as toshort-cirincrease the speed of the armature. Since both of the coils ofswitches S and S are open-circuited at the controller D, neither of themwill close, although switch S will be operated immediately after theoperation of switch S on account of the energization of its coil bycurrent flowing through the auxiliary terminals on the switch S andthrough the fingers 0 and a and the corresponding segments on thecontroller C. The circuit of this coil also includes finger (Z andcontacts d on the controller D for a purpose set forth hereinafter. Theclosing of the switch S will, as before, short-circuit the seriesfield-winding of the motor and will cause a further increase in thespeed of the armature. Switch S will now open; but this will have noeffect, since the entire bank of resistance r is short-circuited by thecontact-fingers and segments of the controller D. Under these conditionsthe motor willbe operating with afull shunt field and its armaturesupplied with current at one hundred and ten volts, which condition willcontinue until the controller C is automatically reversed by themechanism to which it is attached and the segments C of said controllerare brought into engagement with its fingers,

shunt field f of the motor.

Such reversal causes all of the switches S to S to successively open andthe switch S to close, while the armature connections are reversed, soas to cause a reversal of its direction of rotation. When the switch Scloses and establishes the circuit tothe motor, the inertia of thearmature of the motor with its attached load due to their forward motionwill be gradually dissipated as heat in the resistance R armature willthen begin to revolve in the opposite direction, and the switch S willclose when the current has fallen to the predetermined volume. Sincethere is no seg: ment in the set of segments 0 corresponding to thefingers 0 and a, the auxiliary terminals on the switch S areinoperative,- so that when the counter electromotive force of the motorhas reached any predetermined point as, for example, ninety voltsthecoil of the switch S will be sufiiiciently energized to close saidswitch, thus supplying the armature of the motor with current at twohundred and twenty volts through the resistance R it being noted thatsaid flow of current takes place from the positive supply-mainthroughsaid resistance from the upper to the center terminal of the switch Sthrough the controller C, armature A, and series field-winding F of themotor to the negative supply main. When the counter electromotive forceof the armature has risen to one hundred and eighty volts, the coil ofthe switch S will be energized sufficiently to close the same, thusshort-circuiting the resistance R and permitting current to flow to saidcoil through the auxiliary contacts on the switch S. The coil oftheswitch S will likewise be energized, thus closing said latter switch andshort-circuiting the series field-winding F. Owing to the fact thatthere is no segment in the set of contacts 0 on the controller 0corresponding to the finger c, the switch S will not be operated, while,on the other hand, the coil of the switch S will be energized by virtueof the completion of its circuit through the finger 0 so as to open saidswitch and throw the bank of resistance r into circuit with the Suchincreased field resistance will weaken the field of the motor to suchanextent that the motor will run at its maximum speed. When the end ofthe idle or return stroke is reached, the controller C is again reversedand the abovedescribed cycle of operations is repeated, it

being noted that on the working strokei. (2.,

when the contacts C are in engagement with the fingers of the controllerCthe motor is supplied with current at one hundred and ten volts with ashunt 'field of maximum strength. On the return stroke the motor issupplied with current at two hundred and twenty volts and has its shuntfield weakened by the insertion of resistance r. If the controller D beturned to the second point, it will be seen that the opening of theswitch S, which The takes place after the short-circuiting of the seriesfield F, will throw into circuit with the shunt field-winding thatportion of the resistance rwhich is included between the two fingerswhich engage segments (Z and (Z of the controller D, thus causing themotor to operate at a higher speed than when said controller is on itsfirst point. If the controller D is moved to its third point, it will beseen that there is no longer connection between the two fingers (Zwhile, on the other hand, the two fingers 6Z7 are electricallyconnected. By this means one end of each of the coils upon the switchesS and S is connected to one terminal of the armature of the motor, whilethe opposite ends of said coils are connected to the otherarmature-terminal, with the result that said coils will be excited bythe counter electromotive force of the armature.

As above described, the switches S and S are adjusted to close when thevoltages applied to their coils are ninety and one hundred and eightyvolts, respectively. Consequently when the fingers of the controller (Jengage the segments C the switches S and S are successively closed, thussupplying the motor with current at one hundred and ten volts.Immediately thereafter switches S and S are operated so as to supplycurrent at two hundred and twenty volts, and this action is followed bythe short-circuiting of the series field, as in the first case. Afurther increase of the speed of the motor on its working stroke issecured by moving the drum of the controller D to other points beyondthis third point, so that more of the bank of resistance r is throwninto circuit with the shunt field-windingf when the switch S is opened,thereby weakening said field and correspondingly speeding up the motor.

While I have shown but two switches for controlling the resistance R andR it will be understood that, if desired, I may increase this numberwithout in any way departing from the principles of my invention and mayalso Vary the number of switches for throwing resistance into circuitwith the shunt fieldwinding of the motor.

It will be noted that the resistance 7- may, if desired, be madeadjustable. so that the speed of the motor may be varied for bothdirections of rotation of the armature, as indicated, for example, inconnection with the arrangement of my system illustrated in Figs. 1 and2.

Referring to Fig. 4, it will be seen that I have shown my improvedsystem of control as applied to the operation of a shunt-wound motorsupplied with current at any of six voltages delivered from the fourwires of a multivoltage system. With such an arrangement of parts I varythe speed of the motor by supplying its armature with current at theseveral voltages and also, if desired, by varying a relatively smallamount of resistance in the shunt field-circuit.

Fig. 5 indicates diagrammatically a multivoltage system in common use inwhich there are three generating-armatures X, X, and X supplying lines:0, w, (/1 and m. If it be assumed that the armature X generates currentat fortyfour volts, X current at sixtysix volts, X current at onehundred and four volts, it is obvious the following voltages will beavailable: between the lines a; and a", fortyfour volts; between thelines a2 and .11 sixtysix volts; between the lines and :0 one hundredand ten volts; between the lines 0 and in", one hundred and forty volts;between the lines (0 and :0 two hundred and six volts; between the linesa; and 111 two hundred and fifty volts.

In Fig. 4:, Q is a four-pole main switch inserted in the supply-linesr0, r0, a, and 01 As before, 0 indicates a controller operated,preferably, by the driven machine, and for the combination describedthis controller is provided, in addition to the main contact-segmentsand fingers hitherto noted, with two fingers c and 0 having two pairs ofelectrically-connected contact-segments suitably placed upon the same,one of these pairs being included in the set of contacts O and the otheramong the contacts G In addition there is among the set ofcontact-segments C a short segment having a corresponding contact-finger0 while on the side of the controller-drum having the segments C is agroup of segments all connected together and to the maincontact-segments, which engage the fingers c and c and having fivecontact-fingers 0 to 0 placed on the controller, so as to respectivelyengage them. Similarly the contact-segment engaged by the finger 0 isconnected to the segments engaged by the fingers 0* and c. The armatureof the motor is indicated at A and its shunt field at said field beingconnected between the supply-mains w and m and having in series with itan adjustable resistance f. S to S inclusive, are double-poledouble-acting automatic switches each provided with a magnet-coil bywhich it is actuated, and each having pivoted blades .9 and s yoked to abar connected to the armature of its operating magnet-coil 8 Undernormal conditions with the coil not excited the switch-blade s isretained in engagement with the terminals 8 and the blade 5- inengagement with the terminal .9 while when the magnet is excited bothblades are simultaneously turned on their supportingpivots, so as tobreak contact with the terminals s and s and respectively make contactwith the terminals -9 and 826. The pivoted blades 8 of each of the sixswitches when considered in connection with the contacts is designed toconnect the contact-finger 0* of the controller G to certain of thesupplymains, while the switch-blades s in'connection with the terminals8 are designed to connect the contact-fingers with certain others ofsaid supply-mains. When the coil of the switch S is excited, thecontact-finger 0 of the controller 0 is connected to the supply-line inthrough the various switches, While the contact-finger c issimultaneously connected to the line w, thus supplying to the armatureof the motor current at the voltage which exists between the lines 00and m. When switch S is closed, the movement of the blades 8 and .9 upontheir pivots breaks connection with the terminals 8 and 8 of switch Sand causes them to engage with the contacts 8 and s of said switches Sthus connecting the contact-fingers a and 0 of the controller C with thecontact-mains as and 00 whereby current at the next higher voltage issupplied to the armature. In a similar manner each succeeding switch asit operates breaks the connections established by the preceding switchand connects the contact-fingers c and c with the supply-mains, givingcurrent at regularly-increasing voltages. One end of the coil 8 of theswitch S is connected to the supply-main 06, while the other end isconnected to contact-fingers of the controller C. There is a secondcontact-finger 0 connected to the supply-main w, and these two fingersare so placed on the controller as to engage under operating conditionswith one of the two pairs of electrically-connected segments abovenoted, thus energizing the coil of said switch S One end of each of thecoils of the switches S and S is connected to one terminal of thearmature of the motor, while the other end of each of the said coils isconnected, respectively, to the contact-fingers 0 0 to 0 placed on thecontroller C so as to engage the corresponding contactsegments which, asbefore noted, are in connection with the segments engaged by the fingersa and 0 In addition to the above-mentioned controller G there is asecond controller E, having a drum operative at will, which is shown asdeveloped in Fig. 4 and provided with six electrically-connectedsegments (designated by the reference-letter c.) The longest of thesesegments has a corresponding contact-finger e in electrical connectionwith the contactfinger 0 on the controller C, and there are on thecontroller E five other contact-fingers e e toe electrically connectedto the fingers 0 6 to 0 0f the controller and so placed as torespectively engage the various segments .9 when the controller E isoperated. With such an arrangement of apparatus and connections and withthe barrel of the controller C turned so as to bringits contacts 0 intoengagement with the various contact-fingers and the barrel of thecontroller E turned so as to bring all of its contact-fingers intoengagement with their respective segments the coils of each of the fiveswitches S to S inclusive, will be connected across the terminals of thearmature A of the motor, so that they will be excited by the counterelectromotive force thereof.

with the voltages noted between the various supply-mains the coil of theswitch S will be adjusted to operate its switch when the counterelectromotive force of the armature has reached, say,'eightyfive percent. of forty-four volts. Similarly switch S is adjusted to close whenthe counter electromotive force of the armature is increased toeightyfive per cent. of sixty-six volts, and so on, it being seen thatthe armature of the motor will have its speed gradually accelerated asthe switches successively close and apply to it current at the variousprogressively-increased voltages.

Among the set of contacts 0 of the controller C there is no segmentcorresponding to the contact-finger 0 so that the controller E will berendered inoperative when the barrel of the controller 0 has been turnedso as to bring the contact-segments (J into operation. It will be noted,however, that when said set of segments C is in use the contact-fingers0 0 to 0 will engage certain segments, so that under these conditionsall of the switches S to S will be successively operated so as toaccelerate the motor to its highest speed.

The switch S is provided with a second magnetic coil 8 and has a plungerconnected to its blade 8 Said blade is constructed to complete a circuitbetween two contacts 8 and connected, respectively, to the terminals Aof the armature by lines of which one is in series with the bank ofresistance R. The coil 8 is connected directly across the terminals ofthe armature, so that it is constantly excited by the counterelectromotive force of said armature so long as this latter .is inmotion. WVith such connections it will be noted that as long as theswitch S is in position to bridge the contacts 8 and 3 the armature ofthe motor will be short-circuited upon itself through the resistance R.The two coils of said switch S are so designed that when they are bothexcited and with the armature of the coil 8 in position to cause theblades 8 and 8 respectively, to engage the terminals 8 and s the coil 8will be inoperative, since the coil 8 will exert a relatively morepowerful pull on account of its armature being in a practically closedmagnetic circuit, While the coil 8 will be acting upon its armaturethrough a relatively large air-gap. As soon, however, as coil 8 isdeenergizedas, for example, by the operation of the controller Cthe coil8 being still excited by the counter electromotive force of the armaturewill at once operate the switch S after which, even though coil 8 beagain excited, it will retain said switch in position to bridge thecontacts .9

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and 8 until the counter electromotiveforce of the armature has fallen tozero, when the coil 8 is again free to act. 7

Considering the above-described combination of apparatus through onecomplete cycle of operations with the controller E upon its second pointand the resistance r all in circuit with the shunt field of the motor,if the group of segments C of the controller C be brought intoengagement with their respective fingers the coil 3 0f the switch S willat once be connected across the supply-mains w and :13, thus bringingthe blades 8 and .9 into engagement with their respective terminals 8and 8 By following the connections it will be seen that current atforty-four volts is supplied to the armature ofthe motor, and it willtherefore start to rotate. Since the controller E is on its secondpoint, it will be seen that the coil of the switch S will be excited andwill close said switch when the counter electromotive force of thearmature has risen to eighty-five per cent. of forty-four volts, thussupplying the armature with current at sixty-six volts. Since one end ofeach of the coils of the remaining switches is open-circuited both atthe controller C and at the controller E, none of said switches will beoperated, and the motor will continue to run on current at sixty-sixvolts. WVhen the end of the working stroke of themachine operated isreached, the drum of the controller 0 will be automatically moved, so asto open circuit and among other connections the coil .9 of the switch SSince the coil .9 is constantly excited by the counter electromotiveforce of'the armature, it will at once operate the switch S so as tobridge the contacts and .9 while in the meantime the contact-fingers ofthe controller C have been brought into engagement with the set ofcontact-segments C Though the coil .9 of the switchS will thusagain beexcited, it cannot operate said switch until the armature of the motorhas been brought to a standstill in the present instance by beingshort-circuited upon itself through the resistance R. As soon as thisoccurs the coil 8 will operate the switch S and close it, so as tosupply current to the armature at forty-four volts, turn ing saidarmature in a direction the reverse of that first noted on account ofthe reversal of connections in the controller 0. Since the -speed. Atthe end of this stroke of the machine operated the circuits of all ofthe switchcoils will be broken by the operation of the controller C andthe coil 8 will again act to operate the switch S so as to againdissipate athe energy contained in the armature and the parts-attachedthereto in the resistance R, at-

ter which the coil 8 of this switch will again operate it and the abovecycle of operations be repeated.

It will be understood by those skilled in the art that by changing theposition of the ad justable arm of the fieldresistance f the field ofthe motor may be weakened to any desired extent and the speed of themotor thus varied. Similarly by changing the position of the drum of thecontroller E the speed of the motor when the set of contacts C of thecontroller C is in use may be varied to anydesired extent to suit thework operated upon. It will be further seen that, as noted in connectionwith the first application of my invention, the speed of the motor. maybe independently varied during its operation on the idle or returnstroke of the machine operated.

When it is desired to stop the motor, the switch Q may be opened, or thecontrollerC acting in either case to close the armature-circuit throughthe resistance B, so as to quickly bring the armature to rest.

I claim as my invention-* 1. The combination of an electric motor, areversing-controller actuated thereby, with switches operativelyindependent of the controller for governing the application of currentto the motor after said controller has been operated, substantially asdescribed.

2. Theeombination of a motor,an automatic reversing-controller actuatedby said motor including means for operating the same, means foraccelerating the speed of the motor and means operative independently ofthe controller for governing the action of said accelerating means,substantially as described.

3. The combination of a motor, a reversingcontroller operated thereby, aseries of switches, with connections between said apparatus so arrangedthat operation of the controller causes the switches to be successivelyv operated, substantially as described;

4. The combination of a motor, a series of switches having connectionsto the motor such that their successive operation will cause the speedof the motor to be accelerated, and an automatic reversing-controlleractuated by said motor, substantially as described.

5. The combination of a motor, a series of automatic switches and anautomatic reversing-controller connected to cause actuation of saidswitches, said controller being operated by said motor, with means forgoverning the action of said switches and thereby governing the actionof the motor, substantially as described.

6. The combination of a motor with a reversing-controller, a series ofswitches, means for automatically operating the controller andconnections between said apparatus, with means for causing certaincircuits to be broken at the switches before said circuits are broken atthe controller, substantially as described.

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7. The combination of a motor, a reversing controller having main andauxiliary contacts, a series of switches connected to the controller"and to/the'motor, with means connected to said auxiliary contacts foroperating the switches, said contacts being placed to cause the switchesto open before their circuit is broken at the. main contacts of thecontroller, substantially as described.

8. The combination of a motor, a reversingcontroller, automatic switchesconnected socontroller having two sets of contacts, automatic switchesconnected so that their operation causes the speed of the motor to beaccelerated and means for automatically stopping the revolution of themotor, said means including auxiliary contacts placed intermediate ofsaid two sets of contacts, substantially as described.

10. The combination of a motor, an automatic reversingcontrolleractuated by said motor, a series of switches, means for causing theoperation of one of the switches from the controller and meansindependent of the controller for governing the action of the otherswitches, substantially as described.

11. The combination of a motor, an automatic reversing-controllerperiodically actuated therefrom and electromagnetic switches connectedto govern the speed of the motor, the coils on certain of the switchesbeing wound to cause operation of said switches when different voltagesare applied to said coils, substantially as described.

12. In a controlling system the combination of a motor, an automaticreversing-controller and automatically-acting means for absorbing theenergy due to the motion of the armature and its attached mechanismafter each operation of the controller, substantially as described. A

13. In a controlling system, the combination of a motor, an automaticreversing-controller,

a bankof resistance, an automatic switch for placing said resistance incircuit with the shunt field-winding of the motor and means for causingdifferent amounts of said resistance to be in circuit with said windingafter successive reversals of said motor, substantially as described.

14. In acontrolling system, the combination of a motor, an automaticreversing-controller and means operated independently of said controllerfor causing the speed of the motor to be different after successivereversals of said motor, substantially as described.

15. In acontrolliug system, the combination of a motor, areversing-controller, a bank of resistance and an automatically-actingswitch 3 mechanically independent of the controller for 5 throwing saidresistance in circuit with the field of the motor for causing the speedof said motor to bedifferent after successive reversals, substantiallyas described.

16. Inacontrollingsystem, thecombination of a motor, an automaticreversing-controller and adjustable means for causing the speed of .themotor to be different after successive reversals thereof, substantiallyas described.

17 In a controlling system, the combination of a motor, an automaticreversing-controller, a series of automatic magnetic switches, meanscontrolled by said switches for limiting the speed of the motor, withcontacts on the controller for causing certain only of said switches toact after alternate reversals of the motor, substantially as described.

18. The combination of a motor, mechanism operated thereby, a deviceoperated by said mechanism for periodically reversing the motor andautomatically -acting means mechanically independent of said reversingdevice for accelerating the motor after each reversal thereof,substantially as described.

19. The combination in a controlling system of a motor, means forautomatically accelerating the same to a predetermined speed, areversing-controller including means for causing the operation of saidaccelerating means after said controller is operated,with.meansincluding operating mechanism mechanically independent of the controllerfor causing the speed of the motor to be different after its reversalfrom its speed before such reversal, substantially as described.

20. In a controlling system, the combination of a motor, means forcausing the motor to operate at a predetermined speed, an automaticreversing-controller, with adjustable means for causing the motor tooperate after its reversal at a speed diflerent from that before itsreversal, substantially as described.

21. Inacontrollingsystem, thecombination of a motor, adjustable meansfor causing said motor to operate at any predetermined speed, anautomatic reversing-controller and means for causing the motor tooperate after its reversal at a speed different from its speed beforesuch reversal, substantially as described.

22. In a controlling system, the combination of a motor, adjustablemeans for causing said motor to operate at any predetermined speed, anautomatic reversing-controller and adjustable means for causing themotor to operate after its reversal at a speed diflerent from the speedbefore such reversal, substantially as described.

23. The combination in a controlling system of a motor, a switch orswitches, a speed-regulating device connected to be placed in circuitwith the motor by operation of said switch or switches, an automaticreversing-controller and means for causing the motor to operateindependently of said speed-regulating device after alternate reversalsof its direction of retation, substantially as described.

24. In acontrolling system, the combination of a motor, aspeed-regulating device therefor, an automatic switch or switches forplacing said device in circuit with the motor, and an automaticreversing-controller mechanically independent of the switch andincluding means for causing said switch or switches to be 0perated afteralternate reversals of the motor, substantially as described.

I 25. In a controlling system, the combination of a motor, an automaticreversing-controller connected thereto, with a current-limiting deviceand automatic mechanism for throwing said device into circuit with thearmature of the motor after current has been cut ofi therefrom andbefore the application of current for driving it in the reversedirection, substantially as described.

26. In a controlling system, the combination of a motor, an automaticreversing-controller connected thereto, with a current-limiting devicefor the motor and automatic mechanism for throwing said device intooperation after the cutting off of current to the motor and before theapplication of current for driving said motor in a reverse direction,substantially as described. r

27. In a controlling system, the combination of a motor, means forstarting and accelerating the same, an automatic reversing-controllerconnected to the motor and to said means, with a current-limitingdevice, and automatic mechanism for throwing said device into operationafter current has been cut off and before the motor is started in thereverse direction, substantially as described.

28. In a controlling system, the combination of a motor, an automaticreversing-controller connected thereto, a bank of resistance and anautomatic switch connected to throw said resistance into circuit withthemotor after current has been cut off therefrom and before said motor isstarted in a reverse direction, substantially as described.

29. In a controlling system, the combination of a motor, a bank ofresistance, means for completing the circuit through said motor and theresistance, means for automatically cutting out said resistance, meansfor automatically' varying the strengthof the field of the motor whilesaid motor is operating in a given direction and means for automaticallyreversing the motor, substantially as described.

30. In a controlling system, the combination of a motor, a bank ofresistance, means for completing the circuit through said motor and theresistance, means for automatically cutting out said resistance, meansfor varying the strength of the field of the motor and means forautomatically reversing the motor while said motor is operating in agiven direction, said reversing means including connections forautomatically inserting and cutting out said resistance, substantiallyas described.

31. In a controlling system, the combination of a motor, means forvarying the strength of motor-field winding, and a reversing-control lermechanically independent of said switch and including connections forcausing the op eration of the switch after alternate operations of said,controller, substantially as described.

33. In a controlling system, the combination of a compound-wound motor,a bank of re' sistance for the shunt field-winding thereof, with meansfor automatically cutting out the series field-winding, means forvarying the amount of said bank of resistance in circuit with theshunt-winding and means for automatically reversing the motor,substantially as described.

34. In a controlling system, the combination of a compound-wound motor,means for varying the strength of the shunt field thereof, with meansfor automatically short-circuiting the series field-winding and meansfor automatically reversing the motor, substantially as described.

35. In a controlling system, the combination of a compound-wound motor,an automatic reversing-controller therefor, a switch for cutting out theseries winding of the motor, a bank of resistance, a second switch forcausing the insertion of said resistance in circuit with theshunt-winding of the motor and means for causing said switches tooperate successively, substantially as described.

36. In a controlling system, the combination of a compound-wound motor,an automatic reversing-controller therefor, a bank of resistance, aswitch for cutting said resistance out of circuit with the motor, asecondswitch for cutting out the series winding of the motor, a secondbank of resistance, a third switch for causingthe insertion of saidsecond bank ofresistance in circuit with the shuntwinding of the motorand means for causing operation of said switches in a predeterminedorder, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR (J. EASTIVOOD.

IVitnesses:

C. W. CoMsrocK, J. E. WELLMAN.

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